Low-melting-point junction material having high-melting-point particles uniformly dispersed therein

Abstract

A semiconductor device includes a semiconductor element attached to a support member by a junction material that includes a parent phase of a low-melting-point junction material and fine particles of a high-melting-point junction material which are uniformly dispersed in the low-melting-point material. By heating the junction material to a temperature higher than the melting point of the low-melting-point junction material and lower than the melting point of the high-melting-point junction material, the low-melting-point junction material is brought to a molten state, making the entire junction material fluid. Thus, the size of the junction material need not be adjusted to that of the semiconductor element. Further, with this semiconductor device, the contact area between the low-melting-point junction material and the high-melting-point junction material is extremely large so that the requisite time for making the composition of the junction material uniform is shortened.

What is claimed is: 
     
       1. A semiconductor device comprising a semiconductor element;   a support member; and   a junction material disposed between said semiconductor element and said support member for attaching said semiconductor element to said support member wherein said junction material includes a parent phase of Pb-60Sn having a relatively low melting point and fine particles of Pb having a relatively high melting point uniformly dispersed in the parent phase.   
     
     
       2. The semiconductor device as claimed in claim 1 wherein said support member is a die pad. 
     
     
       3. A semiconductor device comprising: a semiconductor element;   a support member; and   a junction material disposed between said semiconductor element and said support member for attaching said semiconductor element to said support member wherein said junction material includes a parent phase of In having a relatively low melting point and fine particles of Pb-5Sn having a relatively high melting point uniformly dispersed in the parent phase.